The present disclosure relates to an imaging device, an endoscope, and an endoscope system.
In recent years, for endoscope systems, a technique for highlighting capillary vessels and mucosal microscopic patterns of a mucous membrane by: irradiation of an observed region of a subject with light of narrow bands (hereinafter, referred to as “narrow band light”) that are narrower than wavelength bands of light emitted by a white light source and that are respectively included in blue and green wavelength bands; and imaging of reflected light reflected from this observed region, has been known (see Japanese Patent Application Laid-open No. 2012-170639). According to this technique, in an imaging element having a color filter provided on a light receiving surface thereof, the color filter having three types of filters arranged in a predetermined pattern, the three types of filters respectively transmitting red (R), green (G), and blue (B), the filters (G-filters) that transmit green components are characterized in that the G-filters are each provided with, in addition to a primary sensitive region sensitive to green light, a secondary sensitive region sensitive to blue narrow band light.
According to the technique described in Japanese Patent Application Laid-open No. 2012-170639, by execution of correlation operations on pixel values of pixels (G-pixels) that receive light that has been transmitted through the G-filters and pixel values of pixels (R-pixels) that receive light that has been transmitted through the filters (R-filters) transmitting red components, pixel values in the secondary sensitive region are extracted from the pixel values of the G-pixels; and based on the extracted pixel values in the secondary sensitive region and pixel values of pixels (B-pixels) that receive light that has been transmitted through the filters (B-filters) transmitting components in the secondary sensitive region and blue components, a highlighted image, in which capillary vessels, mucosal microscopic patterns, and the like of a mucous membrane have been highlighted, is displayed on a display monitor.